Not Applicable.
Traditional systems for characterizing the spectral composition of an optical signal rely upon macro-scale components, or micro-scale versions of such components, that divide the component wavelengths of the input into a spatially or temporally separated output. Spatially-swept systems typically contain a diffractive element, such as a prism or diffraction grating, which may be fixed or rotated. In a fixed configuration, the spatial distribution of the optical output is monitored by an array of detectors. In the rotated configuration, the diffractive element is rotated to sweep the optical output across a single detector. Temporally-swept systems typically incorporate a resonant structure with a finite number of reflective surfaces or structures. The resonator selectively passes or blocks a narrow band of the input spectrum. This band is swept by altering the dimensions of the resonator to produce a temporally-swept output that is monitored by a single detector. Variations on these two themes, such as Fizeau interferometers, exist which incorporate features of both basic approaches.